Microphone pickup and volume control



Dec. 7, 1948. 4,135 ARMQND 2,455,567

y MICROPHONE PICKUP AND VOLUME CONTROL Filed Nov. 14, 1946 IN VEN TOR.

, A WW 0/5 APMO/VD ATTOlP/VZY Patented Dec. 7, 1948 MICROPHONE PICKUPAND VOLUME CONTROL Harry De Armond, Toledo, Ohio, assignor to RoweIndustries, Toledo, Ohio Application November 14, 1946, Serial No.709,864

2 Claims. I

- The present invention relates to an electric pick up device for usewith stringed instruments in which the tones produced may be passed to asuitable amplifier and not only enlarged, but also the individual actionof the string may be changed as desired, and it is an object of thepresent invention to provide a simplified arrangement of parts in whichthe pick up mechanism may be.

suitably located on the face of a stringed instrument and readilyvpositioned with the proper magnets under the proper strings for correctuse of the device; to further simplify arrangement of the several partsand particularly the mounting oi the same on the instrument in additionto locating the same with respect to the pick guard normally used insuch instruments.

A further object of the invention is to provide a unique construction ofrheostat or volume control of a compact type which may be also mountedon the instrument and which is so arranged as to permit the same to bevery economically manufactured and yet provide a large range ofvariation in volume control for the instrument with which it is to beused.

Further objects and advantages are Within the scope of this inventionsuch as relate to arrangement, operation, and function of the relatedelements of the structure, to various details of construction and tocombinations of parts, elements p r se, and to economics of manufactureand numerous other features as will be apparent from a consideration ofthe specification and drawing of a form of the invention, which may bepreferred, in which:

Figure I is a top plan view of my invention applied to a mandolin;

Figure II is a diagrammatic view of the pick up showing formation andlocation with respect to the pick guard of the instrument;

Figure III is a top plan view with the cover of the pick up removed;

Figure IV is a transverse, sectional view taken on the line IVIV ofFigure III;

Figure V is a transverse, longitudinal sectional view taken on the lineVV of Figure III.

Referring to Figure I in the embodiment of my invention illustrated inconnection therewith, I provide a pick up electromagnetic unit l adaptedto be located under the strings of the mandolin as shown in Figure I.The pick up unit has a top cover 12 and a bottom support or base I4. Thecover plate 12 is made of brass and the base l4 may be made of steelsheet metal. The base unit l4 carries the magnet unit and also isprovided with means whereby the complete pick 2 up I0 is supported onthe instrument. To this end, the bottom 16 of the base unit I4 isprovided with a plurality of spaced struck up spring fingers l1 and I8formed from the metal of the bottom l6. Between these spring clips I!and I8 is located a tongue I9 also struck up from the bottom l6 andsince the same may be made of sheet steel these elements may be maderesilient. In order to connect the pick up ID to the instrument, Iprovide a supporting rod 20 which is arranged .to be passed through theeyes formed by the curved fingers l1 and i8 underneath which is thespring tongue is arranged to press the same against the fingers l1 andI8 and hold the rod. 20 by friction in any particular position of adjustment with respect to the pick up l0. Suitable openings 2! and 22 inthe sides of the base unit M are provided through which the rod 20passes so that the rod 20 supports the pick up in this manner.

The other end of the rod 20 is provided witha bifurcated supportingbracket 24, the two ends of which are adapted to slide under the knurlednut of the bridge clamping the bracket 24 in place, and since the rod 20is fixed to the bracket, it will be seen that the pick up I0 issupported therefrom with the magnet unit arranged to be looked under therequired strings of the mando lin.

The electromagnetic unit itself consists of a plurality of cylindricalmagnets =30 insertedinto a plastic core 32 which has a base 33 and a topflange 34 forming, in effect, a spool around which a large number ofturns of extremely fine wire 35 may be wound as required, the sameconstituting the magnet unit 36.

I provide a magnet 30 for each pair of strings of the instrument (oreach single string in a guitar or the like) and accurately align eachmagnet with respect to its corresponding string or strings. Moreover, Ivary the magnetic effect of certain of said magnets for some of thestrings compared with others, This, I accomplish by varying the spacebetween the upper end of the magnet and the strings (as by cutting oifsome of the magnets or lowering them in the core) or by using magnets ofvarying magnetic strength. For instance, I may obtain stick magnets fromNo. 1 to No. 5, graded according to the magnetic power thereof. In thisway, these are made all the same length and arranged under each stringas desired to bring out the correct amplification for that particularstring.

The wires 35 are connected to the microphone cable and to this end, Iprovide a unique method of supporting the cable Ml. To this end, Iprovide the bottom l6 of the base Hi with a tongue 42 adjacent one endthereof which is bent over the cable 40 as shown in Figure III.Moreover, I provide the bottom It with a supporting shelf 43 which hasan end upwardly turned portion 44 with an opening therein through whichthe cable 40 passes to be secured to the wire 35, the tongue 42 beingpressed around the cable M], as shown so that the same is securely andsatisfactorily held in place, and there is no danger of the cable beingdisconnected the magnet wires.

It will be also noted that I provide an attaching and locating pad 41forming an end extension on the base M, the tab or foot M being adaptedto extend under the pick guard and aid in properly locking the pick upit on the instrument.

One suitable means for locking the magnet unit 36 in the base l4consists in providing an anchoring pin or indentation 48 in the'bottomf6 as shown in Figure V, which extends upwardly there-from a shortdistance and through which the plastic core 32 of the magnet unit 36 maybe pressed to properly anchor the unit in the base l4;

Referring to the cover [2, illustrated in Figure II, it will be seenthat the same has a top plate 5!? provided with a longitudinal opening51 a transverse bridge 52 and an end opening 53. The cover 50 has adepending peripheral flange 50 and a small tunnel formation 55 to fitover the cable 40. The cover [2 is retained on the upstanding sides ofthe base 54 by being made to form a press fit thereover and thedepending flange 54 has suitable openings 55 through which the rod 20passes to further secure the cover :2 to the base M.

It will be noted that the bridge 52 forms a reinforcement for the coverand when the cover unit is made of brass this bridge 52 is intended topass under said strings of the mandolin which it is desired nottoamplify in view of the normal string thereof.

It is apparent that, within the scope of the invention, modificationsand different arrangements may be made other than is herein disclosed,and the present disclosure is illustrative merely, the inventioncomprehending all variations thereof.

What I claim is:

1. An electronic pick up device for stringed instruments adapted to belocated between the strings of said instrument and the front facethereof, said device including a relatively thin electromagnetic pick upunit including a core comprising a plurality of vertically arrangedindividual magnets and a body of plastic insulation having a flat topand bottom into which said magnets are inserted; a winding surroundingsaid core; a casing therefor comprising an elongated base having abottom plate; means in said bottom plate to locate said plastic mold inthe casing, said base having a cover therefor, said cover having anelongated opening beneath some of the strings of the instrument betweenthe same and said magnets and a connecting bridge across said opening,said bridge adapted to be located between certain other of said stringsand the corresponding magnet.

2. An electronic pick updevice for stringed instruments adapted to belocated between the strings of said instrument and the front facethereof, said device including a relatively thin electromagnetic pick upunit including a core comprising a plurality of vertically arrangedindividual magnets and a body of plastic insulation having a flat topand bottom into which said magnets are inserted; a winding surroundingsaid core; a microphone cable. for connection to an amplifier; a casinghaving an elongated base having a bottom plate; means in said bottomplate to locate said plastic mold therein; said base having. atransverse extension L adjacent one end; an upstanding outer flangeHARRY DE ARMOND.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,37 6,841 Tirrill May 3, 1-9212,207,341 Dickerson July 9', 1940 2,294,861 Fuller Sept. 1", 1942

